I have a 89' F-250 diesel (e4od trans). When i put it in drive it will shift normally but will not lock-up the torgue converter. also if i put it in first gear manually and hit the throttle it starts to move then slips out. When going down a hill the engine will go to idle with no hold back (in or out of over drive). Is there someway to test these transmissions or check for fuses?? I changed the fluid and filter. the fluid was not burnt. One more thing the O.D. is not blinking. Thank you for any replies!